Air-craft.



CHRISTOPHER JOHN LAKE (NAME CHANGED FROM JOHN CHRISTOPHER LAKE BY JUDICIAL ORDER).

AIR RAHL. APPLIG'ATION Y1LED SEPT.30,1908.

Patnted July 18,1911.

uzfforng.

i RISTOPHER JOHN LAKE (NAME CHANGED PROM JOHN CHRISTOPHER LAKE A BY JUDICIAL ORDER).

AIR CRAFT. APPLICATION FILED SEPT 30, 19084 3 SHEETSSHEET 2.

Zia enter Witnesses:

CHRISTOPHER JOHN LAKE (NAME CHANGED FROM JOHN CHRISTOPHER LAKE BYMJLUDIUIAL ORDER).

AIR CRAFT. APPLICATION FILED SEPT. 30, 1908 Patented July 18, 1911.

3 SHEETS-SHEET 3.

' LAKE,

U[NLTED STATES P TENT OFFICE.

CHRISTOPHER JOHN IiAKE, (NAME CHANGED FROM JOHN CHRISTOPHER itAKE BY JUDICIAL ORDER) or amnenronr, CONNECTICUT.

' AIR-CRAFT.

.To all whom it may concern: I

Be it known that I, CHRISTOPHER JOHN (formerly JOHN CHRISTOPHER L KE acitizen of the United States, and resident of Bridgeport, in the county of F airfield and State of Connecticut, have invented certain new and useful. Improvements in Air-Craft, of which the following is a specification.

This invention relates to that class of aerial machines in. which-the effect of gravity is resisted by the upward components of air pressures acting upon suitably arranged surfaces. The chief 'ditticultyen countered. by this class of devices is .to maintain both lateral and longitudinal stability in the air under varying conditionsof wind and speed. Many experimenters have learned that upon increasing their speed the center of air pressure upon their planes has a distinct tendency to move forward with increaseof speed or wind, thus disturbing the longitudinal stability with the result sometimes of causing the machine to fall t the earth with disastrous and dangerous re .sults. Some ,constructors have sought to minimize this tendency by using planes of short longitudinal dimensions and great lateral spread. Th s, however, increases the head resistance and. also causes "a much greater lateral instability which necessitates fore, of my invention the use of pivoted wing of warping or otherwise lating the ends of the planes soas to equal move through the air,

'strue'ted with ti'on of equipoi-se and by variablewinds or the forceof'gravity alone}.

tips or some means constan y manipume or vary. the pressure thereon and thus "balance the machine. From thefact. above referredto that the stability and poise 01 the devices now known and. used is altered and effected by the speed with-which they they have been con-" articular care to preserve their w en under a given speed and with tooilittle regard" to. maintaining their strbilitylinx-case of failure. offtheir. propel- I lingmjechanism. i v

The general and principal-1 object, therep is-to" construct a. mach'in'e that willtend inherently ltofa condirespective .ofwhether motive powe'rjf'or "by A more particular object to "so dispose and arrange j the J'sustaining surfaces of the machine a that "w enev r. t P QP 'of a generall pointed or narrow at th increasing in width throughout nearly their ofwind contact-.

.any manner thattherefore, the drawings, without reference I I The severa'lsurfaces are secured it is beingacted upon Patented July 18, 1911.

. Serial No. 455,537.

power is cut off, either by accident or by design, the machine can drift or glide in none other but a forward direction and with gradual descent toward the earth.

A further object is to so proportion and design the air impinging surfaces as to. ob-

viate or compensate the Well-known tendency of the center of-air pressure or lift to move forward thereon when there is an increase of speed or when encountering gusts of wind.

A further ob ect is to so arrange the propellingdevice that. the current of air-set up thereby Wlll envelop the machine and cause it to ride on its own created current, thus also protecting it from the effects of uneven wind against its surfaces. 4

With'the above objects in view and such further objects as will appear when the particulars are more fullydisclosed, I have invented certain-improvements in aerial craft which I have embodied in the form of construction that I shall describe by reference to the accompanying drawings, in which,

Figure 1 IS a side elevation, Fig. 2 is a .top view,'Fig. 3 is a front elevation, Fig. 4

is a section on line 44 of Fig.1, and Figs. 5, 6 and 7 ar'etypical longitudinal sections through the supporting surfaces. Similar reference numerals refer to corresponding parts-tliro-ughout the drawings.

The machine consists mainly in a series (if-superposed lifting surfaces 1, 2, 3 and t ofsimilar form and contour, but increasing in s ze from bottom. to top. These surfaces are ofpeculiar and novel formation, being y triangular or wedge shape,

entire length, and being of concave form both'laterally and longitudinally on the side shape,ystreng'th and lightness, They are,

proper relation by a verticaljplane or 'web 5 lower portions,

e forward end and Thesesurfaces may be. constructed of any preferred materials and in will secure the desired to any partogether in which for lightness 'or appearance maybe given a perforated'or" skeleton form in its 'The'surfaces are also .con-- *at'their edges by the members 7 extendin'zfbetween'them; j A platform or'car 8 is suspended beneath the lowermost surface by hangers 9 and 10 and is further sup-.

ported by cords or wires 11 extending from the lower supporting surface 1. This platform carries an engine 12 from which power is conveyed by the sprocket chain 13 to the shaft 14 Whiclrcarries the propeller 15 in ing surfaces is clearly illustrated in Fig. 4,

and the longitudinal curvature by Figs. 5,

6 and 7. This double curvature of the surfaces increases their sustaining power and improves the stability of the machine, espec'ially when the series of surfaces is arangedas shown with each one extending beyond the edges of the one below, so as to collect in its concave portion the upward pressure of the air. v

It will be noted by reference to Figs. 5, (S

and 7, which are sections taken through lines 5-5, (3-43 and 77 of the uppermost surface 4 and which are typical of corre. sponding sections through all of the surfaces, that the forward portion is approximately straight and thatthe curvature incrcases toward the after end. This in con ncction with the constantly increasing width of the surfaces toward the after portion is an important feature for overcoming the tendency exhibited by the usual forms of planes of acquiring under a condition of speed and excessive pressure upon their forward port.ion-a pressure which so increases the angle of incidence of the wind that the machine will be raised forward and thrown backward with dangerous results; The phenomenon of the advancing center of upward ]')rcssurc is believed to be due to disturbances attcnding the sudden in'lpact and deflection of the air upon meeting the forward edge of the plane. I obviate this elt'cct by reducing the forward edge to a point. or to' very narrow dimensions and causing the disturbance due to the initial etlcct of the wind on the plane to be distributed over the greater part of the sides of I thc,support1ng surfaces instead of being concentrated at. the extreme forward edge, and so much of the disturbance or increascd pressure'as docs take place in that portion is limited in its cll'ccts to a very much reduced area of surface. The increasing downward curvature toward the rear of the lifting surfaces also contrilnitcs to confine the center of upward pressure to its normal position. The currents of air meeting or traversing the curve act upon it with a continually increasing angle of incidencetoward the rear. This increases the upward component of air pressure in that portion and serves to counterbalance whatever excess of forward air' pressure has not already been prevented by the reduced area and angular form of that portion. By this means a longitudinal equilibrium of forces is maintained throughout variations of speed and wind. If the propelling device is stopped or becomes disabled the machine cannot fall sidewise owing to the vertical plane or partition between the sustaining surfaces and the form of the surfaces wit-h their greater are: at the rear insures that the machine will take a forward as well"as downward course. The propulsion which results from this gradual descent now serves in lieu o f the propelling power that has been lost andthe triangular form and increasing curvat-ureof the supporting surfaces continues to prevent any advance of the center of upward pressure sufficient to tip up the surfaces and 'slacken the speed and cause-irregular and dangerous gyrations 1n the air. The machine will glide gradually to the earth in a straight course without special guidance or under control of the operator.

Another important advantage arising from the-rcarwardly broadened supporting surfaces with the propeller at the front is that the surfaces are so arranged as to be acted upon over their entire area by the current of air sent back by the propeller which reduces all gusts, eddies and the like 11'- regularities of wind to-a re ular and constant stream which is first concentrated on the for 'ard part of the surfaces and spreading out envelops them entirely with its influence. The machine may thus much more easily rise in the air by reason of creating and directing an artificialcurrent of air to act upon the entire area of its lifting surfaces which when properly proportioned to the wcight and power will cause the machine to ascend immediately without need of a running start or special launching apparatus.

A machine of the ch: actor and simplicity that l have described has also the advantage of being easily constructed so as to be readily assembled or hnochcd down for storage or traiisporta-tion, in which case the concave sustaining surfaces can be ncstcd togcthcr and the. Whole formed into a convenient parcel. These features should render the machinepeculiarly adaptable to naval and military purposes.

Having now described a form of apparatus which embodies my invention, what. l claim is:

1. A flying machine having, in combination, a series of'superposcd concave sustaining surfaces ot' a gcncrally lriangula and and longitudinally.

forwardly pointed sha e and a propeller located in front of said series, each of said sustaining surfaces being larger and extending beyond the edges of the one below.

2. A flying machine having, in combination, a series of superposed concave sustaining surfaces of a generally triangular and forwardly pointed shape and a propeller located in front of said series, each of said sustaining surfaces bein larger and extending beyond the edges of the one below and being concavely curved both transversely 3. A flying machine having "a series of superposed concave sustaining surfaces and a vertical plane or web extendin between them, said surfaces being concave y curved b'oth transversely and longitudinally.

4. A flying machine having a series of superposed concave sustaining surfaces and a vertical plane or web connected longitudinally to the uppermost of the sustaining surfaces, said uppermost surface being con- 'between them,

cavely curved both transversely and longitudinally.

5. A flying machine having a series of superposed concave sustaining surfaces of a generally triangular and forwardly pointed shape'and a vertical web or plane extending each of said surfaces being larger than and of the one below.

6. A flying machine having a series of superposed concave sustaining surfaces of a generally triangular and forwardly pointed shape and a vertical web or plane extending between them, each of said surfaces being larger than and extending beyond the edges of the one below and being concavely curved b'oth transversely and longitudinally.

Witnesses:

E. A. Jonson, C. E. ADAMS.

extending beyond the edges 

